United States
Environmental Protection
Agency
Industrial Environmental Research ;
Laboratory ~
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-111 Sept. 1984
Project Summary
Wastes from Manufacture of
Dyes and Pigments
David C. Bomberger, Julia E. Gwinn, and Robert L. Boughton
A preliminary study of the manufac-
ture of dyes and pigments was con-
ducted to determine if process waste
streams might contain hazardous mate-
rial. The study first identifies the dyes
and pigments that belong to the major
segments of the industry, the amounts
produced, and the known U.S. pro-
ducers. The chemistry of these dyes and
pigments is discussed as well as the
overall production process and waste
treatment practices. Waste streams that
could contain hazardous material are
identified and companies that produce
representative dyes and pigments are
recommended for a sampling program
to confirm the composition and amounts
of these waste streams.
This Project Summary was developed
by EPA'*Industrial Environmental Re-
search Laboratory, Cincinnati, OH, to
announce key findings of the research
project that Is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The Resource Conservation and Recov-
ery Act (RCRA) requires that hazardous
solid wastes produced by manufacturing
operations be identified and disposed in a
manner that limits the release of hazard-
ous materials to the environment. To
date, many specific waste streams from
manufacturing processes have been listed
in regulations as being hazardous be-
cause of their chemical composition. The
objective of this preliminary study is to
help determine if wastes produced by the
manufacture of dyes and pigments in the
United States might require listing as
hazardous materials. An analysis of both
the chemistry and the physical processing
involved in dye and pigment manufactur-
ing will be used to identify all wastes that
may contain significant chemical hazards.
An analysis of the industry will be used to
determine specific manufacturers where
the candidate wastes are produced. This
information will help the U.S. Environ-
mental Protection Agency, Office of Solid
Wastes, to design a sampling and analysis
program to confirm or disprove the pre-
sence of hazardous materials in the
candidate wastes and thereby develop a
basis for listing dye and pigment manu-
facturing wastes under RCRA. This report
summarizes the content of nine reports
covering the following dye and pigment
classes:
Volume I: Azo Dyes and Pigments (Ben-
zidine and Its Congeners)
Volume 2: Azo Dyes and Pigments (Ex-
cluding Benzidine and Its Congeners)
Volume 3: Stilbene Dyes and Fluorescent
Brightening Agents
Volume 4: Anthraquinone Dyes and Pig-
ments
Volume 5: Diphenylmethane and Triaryl-
methane Dyes and Pigments
Volume 6: Methine and Polymethine Dyes
and Pigments
Volume 7: Xanthene Dyes and Pigments
Volume 8: Phthalocyanine Dyes and
Pigments
Volume 9: Sulfur Dyes
Discussion
Amongthe commonly recognized struc-
tural classes of dyes and pigments, the
most important commercially in the Unit-
ed States are the azo dyes and pigments.
The 1978 U.S. production of azo dyes and
pigments was approxi mately 41,000 met-
-------
ric tons or about 35% of all U.S. dye and
pigment production. These dyes and
pigments are characterized by the pres-
ence of one or more azo groups—(-N=N-)
in the molecule. Consequently, the class
can be divided into subclasses (monoazo,
disazo, trisazo, tetrakisazo, and polyazo).
A special subclass consists of azoic com-
pounds, namely, azoic coupling compo-
nents, azoic compositions, and azoic
diazo components, that are reacted on the
fiber to produce azo dyes. The azo dyes
and pigments class can also be divided
into groups of dyes and pigments pro-
duced from one common, structurally
related group of starting materials. One
such group of starting materials consists
of those substituted biphenyls having
amine groups in both para positions (i.e.,
benzidine and related compounds having
additional substituents in the two rings).
Theoretically, this group can include a
very large number of compounds, but
commercially significant dyes are pro-
duced from only a limited number of com-
pounds.
The stilbene dyes share in common the
structural constituent 2,2'-stilbenedisul-
fonic acid. However, the chromophoric
system of the stilbene dyes is due to the
presence of an azo or azoxy group. Even
though the stilbene dyes are a subdivision
of the azo class, they are treated as a
separate class because they are not
prepared by the classical azo coupling
reaction. Many fluorescent optical bright-
eners are also based on stilbene deriv-
atives and these are included in the
Colour Index (The Society of Dyers and
Colourists, 1980) with the stilbene dyes.
According to the U.S. Tariff Commis-
sion (1974), the U.S. commercial pro-
duction of stilbene dyes and brighteners
for 1972 was 14,000 metric tons. This
represented 12% of the total reported
U.S. commercial dye production of
120,000 metric tons for that year. The
stilbene dyes and fluorescent brightening
agents represented the third largest
structural class of dyes based on U.S.
commercial production volume. Approx-
imately two-thirds of the stilbene dyes
and brighteners production was attrib-
utable to the fluorescent brightening
agents. Data on U.S. production of dyes
by structural class have not been reported
si nee 1972; therefore, it was not possible
to determine from public sources whether
the relative importance and total produc-
tion of stilbene dyes and brighteners has
changed.
In 1972, production of 21,200 metric
tons for all anthraquinone dyes was
reported to the U.S. Tariff Commission
(1974). This represented 18% of the total
reported dye production. Anthraquinone
dyes and pigments represented the sec-
ond largest structural class of dyes based
on U.S. production volume. An industry
contact indicated that during the last few
years U.S. commercial production of
anthraquinone dyes has decreased signif-
icantly.
The diphenylmethane and triarylme-
thane dyes and pigments are among the
oldest synthetic dyes. They give dyeings
of extreme brightness and purity, but
their fastness properties, particularly to
light, are quite poor. Despite their light
fugitiveness, these dyes and pigments
are widely used because of their brilliant
shades, their extremely high tinctorial
values, and their relative low cost. In
1972, production of 4000 metric tons for
all triarylmethane dyes (this figure in-
cludes diphenylmethane dyes) was re-
ported to the U.S. Tariff Commission
(1974). This represents 3.4% of the total
reported U.S. dye production of 120,000
metric tons for that year. Diphenylme-
thane and triarylmethane dyes and pig-
ments represented the fourth largest
structural class of dyes based on U.S.
production volume. Data on U.S. produc-
tion by structural class have not been
reported since 1972; therefore, it is not
possible to determine from public sources
whether the relative importance and total
production of these dyes and pigments
have changed.
In 1972, production of 2,500 metric
tons for all methine and polymethine dyes
was reported to the U.S. Tariff Commis-
sion (1974). This represents 2% of the
reported U.S. dye production. Methine
and polymethine dyes and pigments
represented the fifth largest structural
class of dyes based on U.S. production
volume. Data on U.S. production by
structural class has not been reported
since 1972, so it is not possible to deter-
mine from public sources whether the
relative importance or total production of
methine and polymethine dyes and pig-
ments has changed.
The xanthene dyes and pigments are
characterized by pure, brilliant hues, by
fluorescence, and by a range of colors
from yellow to violet. In 1972, production
of 530 metric tons for all xanthene dyes
was reported to the U.S. Tariff Commis-
sion (1974). This represented 0.4% of the
total reported U.S. dye production of 120,
000 metric tons for that year. The xan-
thene dyes and pigments represented the
ninth largest structural class of dyes
based on U.S. production volume. Data on
U.S. production by structural class has
not been reported since 1972, so it is not
possible to determine from public sources
whether the relative importance or total
production of xanthene dyes and pig-
ments has changed.
The phthalocyanine dyes and pigments
are brilliant and greens that are stable
with respect to heat and light, acid, and
alkali. They are used in paints, lacquers,
inks, plastics, and rubber. For fiber dyeing,
the phthalocyanine pigments can be
made into temporarily soluble dyes that
are subsequently insolubilized on and in
fibers. Soluble phthalocyanine pigments
precursors can be printed on fiber and
cured with heat to form the insoluble
pigments. Solubilizing groups such as
sulfonates can be added to make direct
dyes for paper, cotton, and other textile
fibers. Finally, additional chemical modi-
fication can add fiber-reactive groups for
dyeing cotton.
The U.S. Tariff Commission (1974)
reported a total 1972 production of 628
metric tons of phthalocyanine dyes and
6350 metric tons of phthalocyanine pig-
ments. U.S. total production of dyes and
pigments by chemical class was not
reported for 1979 (U.S. International
Trade Commission, 1980), but data from
the Organic Dyes and Pigments Data
Base prepared by SRI International
(USEPA, 1984) shows a total dye produc-
tion of greater than 491 metric tons and a
total pigment production of greater than
8198 metric tons. Thus, pigment produc-
tion grewsubstantially(29% minimum) in
the seven-year period. If phthalocyanine
dye production had grown as much, it
would have been 810 metric tons, which
would mean that production of phthalo-
cyanine dyes would have increased by
182 metric tons from 1972 to 1979.
Sulfur dyes have been produced com-
mercially for more than 100 years. In
spite of this long history and unlike most
dyes of other classes that are clearly
defined compounds of known structure,
the sulfur dyes are, with few exceptions,
mixtures of variable and unknown compo-
sition. There is disagreement as to what
defines a sulfur dye. The early sulfur dyes
formed a chemical class in that they were
prepared from sulfurization or "thiona-
tion" of relatively simple intermediates
with either sulfur or sodium polysulfide.
They also formed a dyeing class in that, as
water-insoluble substances, they were
brought into soluble form for dyeing by
treatment with a hot solution containing
alkali and sodium sulfide. However, some
newer dyes synthesized by a thionation
procedure but dyed from an alkaline
dithionate vat (sodium hydrosulfitevat) in
-------
the manner of vat dyes were introduced.
Some argued that "sulfur dyes are best
defined as those dyes which are applied
in a reduced state from solutions contain-
ing sodium sulfide, hydrosulfide, or poly-
sulfide and which are subsequently oxi-
dized on the fiber" (Orton, 1963). This
definition precluded dyes made by a
thionation procedure that were applied as
vat dyes. However, in the listing of dyes by
classes in the Colour Index (1980), the
"sulfurized vat dyes" are included in the
sulfur dye chemical class. Therefore, we
included these dyes in this study.
The total production volume of sulfur
dyes is not known. In the mid-1960s, the
U.S. production of sulfur dyes ranged
from 8100 to 9100 metric tons per year,
representing 7% to 8% of total dye
production(U.S. Tariff Commission, 1965,
1967, and 1968). The importance of
sulfur dyes as a commercial class has
declined (Allen, 1971), although they are
still in demand because of their moder-
ately good properties and low cost.
Summary and Conclusions
In this preliminary study of dyes and
pigments, several waste streams were
identified that might contain hazardous
materials:
• Discarded shipping containers. These
would be paper bags and fiber drums
used to transport dye and pigment
intermediates and would contain a
residual amount of intermediate when
emptied.
• Solid residues from process synthesis,
distillation, and filtration. These would
contain unreacted dye intermediates,
reagents, and reaction by-products.
• Filter cake from clarifying operations.
This cake could contain dye, unreacted
intermediates, solvent, by-products
formed in the synthesis of intermedi-
ates, metallic catalysts, and other
impurities.
• Still bottoms in the production of
anthraquinone dyes and pigments
from the recovery operations of many
of the organic solvents—chloroben-
zene, o-dichlorobenzene, acetone,
xylene, nitrobenzene, isobutyl alcohol,
naphthalene, phenol, and pyridine.
• Gaseous emissions that may contain
nitrogen oxides (stilbene dye manufac-
ture); phosgene, formaldehyde, nitro-
gen oxides and arylamines (diphenyl-
methane and triarylmethane dye and
pigment manufacture); ethylene oxide,
formamide, arylamines and chlorina-
ted aromatic solvents (phthalocyanine
dye and pigment manufacture); and
hydrogen sulfide (sulfur dye manufac-
ture).
• Process wastewater that may contain
mother liquor from filtering operations.
This is probably the major source of
discharge of organic chemicals from
most stilbene plants. In phthalocyanine
dye and pigment manufacture, organic
materials and heavy metals from the
various synthesis steps and PCBs may
be present. Brines in the manufacture
of sulfur dyes contain inorganic sulfur
compounds and some organic com-
pounds. Process wastewater from the
manufacture of diphenylmethane and
triarylmethane dyes and pigments
may contain organic materials and
heavy metals.
• Wastewater treatment solids. The
evidence suggests that the solids will
be contaminated with low levels of all
of the dye and pigment intermediates
as well as the dyes and pigments
themselves and some reaction by-
products. If these solids are placed in a
landfill, intermediates may be released
as a result of reduction of the azo
linkages under the anaerobic condi-
tions prevailing in the landfill.
• Baghouse fines. The fines are gener-
ated during the drying, standardizing,
and packaging of the dyes and pig-
ments. The fines will be principally the
dyes and pigments and inert salts.
Anaerobic conditions in a disposal site
could cause intermediates to be re-
leased from these fines.
Information on the producers of dyes
and pigments and production volume
information were analyzed to choose
representative production facilities where
a sampling program might be conducted
to determine the composition of the
waste emissions. The following compa-
nies are recommended by dye class:
Azo dyes and pigments
(exluding benzidine)
American Color and Chemical Corp.
American Cyanamid Co.
Atlantic Chemical Corp.
E. I. Du Pont de Nemours & Co., Inc.
Harshaw Chemical Co.
Toms River Chemical Corp.
Azo dyes and pigments
(benzidine and its congeners)
Fabricolor, Inc.
Sterling Drug, Inc.,
Hilton Davis Chemical Co. Div.
Sun Chemical Corp.
Atlantic Chemical Corp.
Crompton & Knowles Corp.
Toms River Chemical Corp.
Stilbene dyes and fluorescent
brightening agents
American Color & Chemical Corp.
American Cyanamid Co.
Ciba-Geigy Corp.
Toms River Chemical Corp.
Mobay Chemical Corp., Dyestuff Div;
Anthraquinone dyes and pigments
Toms River Chemical Corp.
American Color & Chemical Corp.
American Cyanamid Co.
BASF Wyandotte Corp.
Eastman Kodak Co.,
Tennessee Eastman Div.
Mobay Chemical Corp.,
Dyes & Chemical Div., Lowell, NC
Crompton & Knowles Corp.,
Dyes & Chemical Div., Lowell NC
Diphenyl methane and triarylmethane
dyes and pigments
American Cyanamid Co.
Dye Specialties, Inc.
H. Kohnstamm & Co., Inc.
Max Marx Color & Chemical Co.
Sterling Drug, Inc.,
Hilton Davis Chemical Co. Div.
Methine and polymethine
dyes and pigments
Atlantic Chemical Corp.
Mobay Chemical Corp.
BASF Wyandotte Corp.
Toms River Chemical Corp.
Xanthene dyes and pigments
Max Marx Color and Chemical Co.
Sun Chemical Corp.
Sterling Drug Inc.,
Hilton Davis Chemical Co. Div.
Phthalocyanine dyes and pigments
ICI Americas Inc.,
Chemical Specialties Co.
American Hoechst Corp.,
Industrial Chemicals Div.
3
-------
Sun Chemical Corp.
Ciba-Geigy Corp.
American Cyanamid Co.
(Marietta, OH, plant)
Toms River Chemical Corp.
Sulfur dyes
Martin-Marietta Corp., Sodyeco Div.
American Cyanamid Co.
Process Chemistry
A discussion of the process steps
required to synthesize dyes and pigments
will aid in formulating the emission
estimates and is found in the reports on
each major dye class.
Sources of Waste Discharges
During Dye and Pigment
Manufacturing
The wide range of dye and pigment
production processes and the specific
plant characteristics and process control
capabilities make estimating material
losses during dye manufacture a difficult
task. In general, the most significant
material losses are intermediates that do
not react and by-products such as incom-
plete dye or pigment molecules. The
intermediates and by-products from the
dye manufacture are present either in the
product or in the solid waste streams
regulated under RCRA, which include
wastewater, solid residue, and the vapor
and dust emissions. The material in the
wastewater is discharged in the plant
effluent and some is discharged on any
wastewater treatment solids.
The sources of wastes from dye manu-
facture identified in Figure 1 are sum-
marized below:
• Material handling—Airemissionsfrom
raw material dusting and volatilization,
solid residue on shipping containers,
and process wastewaters from equip-
ment washdown.
• Dye syntheses—Air emissions from
the volatlization of intermediates and
by-products from reaction vessels,
solid residuals from distillation resi-
dues and spills, and process waste-
waters from equipment washdown.
• Product and intermediate filtration—
Air emissions from unreacted inter-
mediate and by-product volatilization
during material handling, solid resi-
dues from spills, and process waste-
water from equipment washdown. A
significant additional source of process
wastewater is the mother liquor when
aqueous processes are used.
• Drying—Air emissions from volatiliza-
tion of by-products and unreacted
intermediates in the drying oven, and
solid residues from spills and dusting
of the product dye.
• Grinding, blending, standardization,
and packaging—Solid residues from
dusts produced by the grinding opera-
tions that may be either in the air
streams from vent systems designed
to prevent the material from entering
the workplace environment or as a
solid residue from spills.
• Air pollution control—Solid residues
from baghouses or scrubbers collecting
fine dusts and process wastewaters
from scrubbers.
Each dye producer may have a different
wastewater treatment system. Some
process wastewaters are discharged
directly to sewers and thus to publicly
owned treatment works. Some waste-
waters are sealed in drums, which are
placed in a landfill. Some producers have
on-site wastewater treatment plants. All
these treatment plants will be site-specific
designs with site-specific behavior. Sev-
eral examples of on-site treatment facil-
ities at dye production sites are discussed
to indicate the type of treatment often
used and its effectiveness.
References
Allen, R. L M. 1971. Color Chemistry.
Appleton-Century-Crofts, New York.
Orton, D. G. 1963. Sulfur Dyes. In: Kirk-
Othmer Encyclopedia of ChemicalTech-
nology, Interscience, New York, pp.
424-441.
The Society of Dyers and Colouritsts.
1980. Colour Index. Lund Humphries
Printers, London, England, Volumes 1 -
3, Third Edition, 1975; Additions and
Amendments Numbers 13-36, October
1974-July 1980.
U.S. Environmental Protection Agency.
The Organic Dyes and Pigments Data
Base. EPA-600/1-84-032, Cincinnati,
Ohio, 1984.
U.S. International Trade Commission.
1980. Synthetic Organic Chemicals,
U.S. Production and Sales, 1979. USITC
Publication 1099.
U.S. Tariff Commission. 1965. Synthetic
Organic Chemicals, U.S. Production and
Sales, 1964. TC Publication 167, U.S.
Government Printing Office, Washing-
ton, DC.
U.S. Tariff Commission. 1967. Synthetic
Organic Chemicals, U.S. Production and
Sales, 1965. TC Publication 106, U.S.
Government Printing Office, Washing-
ton, DC.
U.S. Tariff Commission. 1968. Synthetic
Organic Chemicals, U.S. Production and
Sales, 1965. TC Publication 248, U.S.
Government Printing Office, Washing-
ton, DC.
U.S. Tariff Commission. 1974. Synthetic
Organic Chemicals, U.S. Production and
Sales, 1972. TC Publication 681, U.S.
Government Printing Office, Washing-
ton, DC.
-------
Air Pollution
Control
Solid Waste
Wastewater
Grinding,
Blending
Standardization.
and
Packaging
Product
Solid Waste
Process
Wastewater
Process
Wastewater
Process
Wastewater
Mother Liquor
Figure 1. Production operations that are sources of waste emissions in dye and pigment manufacture.
Process
Wastewater
D. C. Bomberger, R. L Boughton, and J. E. Gwinn are with SRI International,
Menlo Park, CA 94025.
M. J. Stutsman is the EPA Project Officer (see below).
The complete report consists of nine volumes, entitled "Wastes from Manufacture
of Dyes and Pigments:" (Set Order No. PB 84-200 864; Cost: $79.50)
"Volume I.Azo Dyes and Pigments (Benzidine and Its Congeners Subsector,"
(Order No. PB 84-200 872; Cost: $ 11.50)
"Volume 2. Azo Dyes and Pigments (Excluding Benzidine and Its Congeners,"
(Order No. PB 84-200 880; Cost: $ 19.00)
"Volume 3. Stilbene Dyes and Fluorescent Brightening Agents," (Order No.
PB 84-200 898; Cost: $8.50)
"Volume 4. Anthraquinone Dyes and Pigments," (Order No. PB 84-200 906;
Cost:$11.5O)
"Volume 5. Diphenylmethane and Triarylmethane Dyes and Pigments,"
(Order No. PB 84-200 914; Cost: $8.50)
"Volume 6. Methine and Polymethine Dyes and Pigments," (Order No. PB
84-200 922; Cost: $8.50)
"Volume 7. Xanthene Dyes and Pigments," (Order No. PB 84-200 930; Cost:
$8.50)
"Volume 8. Phthalocyanine Dyes and Pigments," (Order No. PB 84-200 948;
Cost: $8.50)
"Volume 9. Sulfur Dyes," (Order No. PB 84-200 955; Cost: $8.50)
The above reports will be available only from: (cost subject to change)
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
•&U. S. GOVERNMENT PRINTING OFFICE: 1984/759-102/10691
-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
a*(i " ,
CrUf»t>vj
------- |